The present invention relates to a snap button used for clothes, bags and the like, more particularly, to a snap button which can function as both of a male snap and a female snap.
In general, a snap button is used as a pair of a male snap and a female snap, where the male snap has a projection and the female snap has a recess for detachably receiving the projection of the male snap. Therefore, between the male and the female snaps, steps of manufacture, inventory management, attachment to cloths, etc. are different. To improve this matter, Japanese Examined Utility-Model H06-31929 discloses a technology in which one sort of a snap button can be used as both of a male snap and a female snap. The snap button disclosed in the document includes a pair of male pieces and a pair of female pieces both of which project from a disk-shaped button body. In use, the pair of the male pieces of one of two same snap buttons are fitted between the pair of the female pieces of the other button.
In the snap button disclosed in the document, when the two snap buttons are engaged with each other, it is necessary not only to accurately align the axis of one of the two snap buttons with the axis of the other but also to adjust the circumferential positions of the two snap buttons so as to match the pair of the male pieces of one of the two snap buttons with the pair of the female pieces of the other. Therefore, the act of engaging the two snap buttons has to be performed very carefully. In addition, when the two snap buttons are attached to cloths, they have to be fixed in proper and accurate circumferential positions, which makes the work of attaching buttons to cloths difficult.
In view of the problems as mentioned above, an object of the present invention is to provide a snap button which can function as both of a male snap and a female snap without accurate alignment or positioning two snap buttons to be engaged with each other.    [Patent document 1] Japanese Examined Utility-Model H06-31929